Best way to sort brass?

Discussion in 'Reloading' started by diderr, Sep 10, 2012.

  1. diderr

    diderr Well-Known Member

    Messages:
    432
    Joined:
    Dec 16, 2007
    I know volume sorting is better than just weight sorting, but whats the best way to do it? Is it better to do it with water or just a really fine powder like H414? or is weight sorting the way to go?
    Thanks
     
  2. Bart B

    Bart B Well-Known Member

    Messages:
    2,483
    Joined:
    Dec 25, 2005
    Sort rifle brass to a 1% spread in weight. It's not worth the time, mess and insignificant results to use some method to measure case volume. You have to first fire form the case first to get its dimensions more uniform than virgin brass has. It ain't worth the expense and barrel life for me to do that. Until you're shooting at worst, 1/4 MOA at 100 yards, 1/3 MOA at 300, 1/2 MOA at 600 and 3/4 MOA at 1000, don't waste your time; just weigh cases. Accuracy that good happens routinely by weight sorting and neck turning if neck walls have more than a 1/1000th spread in thickness with good dies and techniques. No other case prep's needed.
     

  3. Mikecr

    Mikecr Well-Known Member

    Messages:
    4,265
    Joined:
    Aug 10, 2003
    The best way to do it is to fully prep & fully fire-form your cases(which you are going to do no matter what), then measure unsized cases with water & ~a drop of alcohol per cup.

    I deprime cases, vibratory clean them, stand them up on a scale with plastic golf tee in the flashole, zero, then eyedrop in the water to the case mouth & touch meniscus with a corner of tissue to level. Get the reading.

    Now regardless of brass performance to that point, you can decide just how matching to have them. Or, you might learn something different that you wouldn't have without the testing. Who knows? And maybe capacity matters for you,, maybe not.
     
  4. diderr

    diderr Well-Known Member

    Messages:
    432
    Joined:
    Dec 16, 2007
    I have got 0.069 moa with the load I have now at 100 yards, and have shot a 2.685" or 0.641 moa group at a 1,000 yards with a similar load I often use. I'm willing to do the extra work of volume sorting. It also helps i'm using Norma brass. I've done almost everything else I can to squeeze every ounce of accuracy out of my system. Volume or weight sorting is about the only thing I dont do.
     
  5. Bart B

    Bart B Well-Known Member

    Messages:
    2,483
    Joined:
    Dec 25, 2005
    Are these stated groups the largest you've produced?

    How many shots per group?

    I think a 2.685 inch group at 1000 is .2685 MOA. I also think a .641 MOA group at 1000 yards is 6.41 inches extreme spread.
     
  6. diderr

    diderr Well-Known Member

    Messages:
    432
    Joined:
    Dec 16, 2007
    You're right on the 1,000 moa. I had my OnTarget set to 400 yards when I referenced it. The 1,000 group was definitely a "screamer" group. It would be nearly impossible for me to reproduce, but it has done it once with perfect conditions. My 100 yards group is usually the norm on good days but can go up to 0.155" depending on the day. Both were three shot groups.
    The point i'm trying to make is that I want to leave no stone unturned in producing as accurate as possible loads for an accurate rifle. Even if there is even a chance of improvement I will at least try it. I'm planning on doing some F-class events next year with this rifle. It might be worth the time for me to do it and leave nothing to chance, or it might just be a "feel good" thing or a "placebo effect"

    When I bought my first batch of Norma I was going to weight sort them, but they were so close that it was pointless to do. I just never gave volume sorting much thought. I would like to run a test or trial with five volume sorted pieces and five pieces chosen at random and shoot them at 600 yards.
    Thanks for your input.

    Mikecr; thanks I might have to try that. I must ask why it's important to add the alcohol?
     
  7. Bart B

    Bart B Well-Known Member

    Messages:
    2,483
    Joined:
    Dec 25, 2005
    That's good. But you might want to decide what "accurate rifle" means for you, too. For example, what's the largest group any load has shot?

    To some folks, it's the smallest few-shot group fired. Doesn't matter if all the other groups are larger. Example, the record 1000-yard benchrest few-shot groups are 2 inches or less. But the many-group average for aggregate records is typically 2/3rds the size of the biggest single group fired. And rarely, if ever, does the rifle and ammo holding the record few-shot group also hold the many-group aggregate record; they didn't shoot well enough (too big of groups) to hold that one, too.

    To others, it's the largest many-shot group fired. That's what can be counted on the vast majority of the time. This is what arsenals do for military ammo; they shoot a couple hundred shots per test group 'cause they want to see what the accuracy level is that can be counted on all the time.

    One thing to note on group shooting; if all the groups fired with a given load are not the same size, you're not shooting enough shots per group to asses the load's performance to count on all the time. Another is, the smaller a given test load's few-shot groups are, the harder it is to shoot one that's smaller than the previous one. For example, which of the below sets of five 3-shot groups at 1000 yards is the most accurate:

    Group set A, ranges from 1 inch to 6 inches.

    Group set B, ranges from 2 inch to 5 inches.
     
    Last edited: Sep 12, 2012
  8. Greyfox

    Greyfox Well-Known Member

    Messages:
    3,710
    Joined:
    Jan 21, 2008
    This is the case if you are using IPHY, or "Shooters MOA". At 100 yards 1 MOA is equal to 1.047". If the group measures 6.41" at 1000 yards it is actually 6.12 MOA. Less than a half inch difference at 1000 yards, but since the post is carrying measurements to more than two decimal points, thought it should be mentioned. This conversion becomes more relevant if you are using a MOA scope and considering inches when adjusting for long range shooting.
     
  9. Mikecr

    Mikecr Well-Known Member

    Messages:
    4,265
    Joined:
    Aug 10, 2003
    Grouping undefined from center is a matter of 'precision', and not 'accuracy'.
    Accuracy is not a shooting marathon, but is defined with a single shots, w/resp to center of mark.
     
  10. Mikecr

    Mikecr Well-Known Member

    Messages:
    4,265
    Joined:
    Aug 10, 2003
    You got that right, as the error at 1kyd would be .47" per IPHY dialed erroneously with a true MOA scope.
     
  11. Pieter Willem Vorster

    Pieter Willem Vorster Active Member

    Messages:
    31
    Joined:
    Jul 3, 2013
    I am a new member - the reason for my late reply to this post
    I want clarity on this issue, ie. case volume and case weight. My limited knowledge of Physics tells me that if you have two cases, A and B, with the same outside dimensions and made from the same alloy, and the weight of A=weight of B, the volume of A=volume of B.
    If this is true, it is only necessary to sort a batch of cases by weight and not by volume.
    Is there anybody with more knowledge about this who can sceintifically confirm my view?
    Please pardon my English. It is nog my mother toung.

    Regards
    Pieter Willem Vorster
     
  12. Bart B

    Bart B Well-Known Member

    Messages:
    2,483
    Joined:
    Dec 25, 2005
    I know of several National champions and record setters in rifle competition who only weigh cases to 1/4 grain, 1/2 grain or even a 1 grain spread and are totally satisfied with their method.

    Some folks feel case capacity is best, but the case has to have virtually the exact same outside dimension as the chamber does to get reliable numbers. Any out of round the case has will effect its internal capacity.

    I weigh cases to a 1 grain spread and have gotten as good of accuracy as anybody at the longer ranges.

    Those who disagree will post their opposing points of view.
     
  13. Bart B

    Bart B Well-Known Member

    Messages:
    2,483
    Joined:
    Dec 25, 2005
    Do you mean calculating the mean radius from a calculated group center of all fired shots?

    Or is it the mean radii of all shot holes from the center of the target you're shooting at?
     
  14. Pieter Willem Vorster

    Pieter Willem Vorster Active Member

    Messages:
    31
    Joined:
    Jul 3, 2013
    Bart B, thanks for responding, but my question is not answered.

    Regards.